We explore an easy-to-implement moiré-based measurement scheme for the mask-wafer misalignment in nanoimprint lithography. By introducing the beat signal of moiré fringes, the measurement range increase by dozens or even hundreds of times, while the measurement accuracy doesn’t get affected and still kept in nanoscale. Moreover, the alignment signal, collected throughout the whole imprint process, is independent of the wafer-mask gap and beam fluctuation, which makes it very suitable for the misalignment measurement in NIL. The experiment shows that sub-10 nm alignment could be obtained within a measurement range of 500µm, which is expected to be improved after the parameter optimization.

中文翻译：

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纳米压印光刻中双频莫尔条纹的未对准测量

我们探索了一种易于实现的基于波纹的测量方案，用于纳米压印光刻中的掩模晶圆未对准。通过引入莫尔条纹的拍信号，测量范围增加了数十倍甚至数百倍，而测量精度却没有受到影响，仍然保持在纳米级。此外，在整个压印过程中收集的对准信号与晶片掩模间隙和光束波动无关，这使其非常适合于NIL中的对准误差测量。实验表明，在500µm的测量范围内可以获得10nm以下的对准，预计在参数优化后会得到改善。